Reproduction apparatus



June 25, 1963 J. SZEKERES 3,094,909

REPRODUCTION APPARATUS Filed May 26, 1959 5 Sheets-Sheet 1 A v" m 2 G N N t w G J O ,4 I) N June 25, 1963 J. SZEKERES 3,094,909

REPRODUCTION APPARATUS Filed May 26, 1959 5 Sheets-Sheet 2 FIG.2

June 25, 1963 J. SZEKERES REPRODUCTION APPARATUS Filed May 26, 1959 5 Sheets-Sheet 3 wdE m QE

5 Sheets-Sheet 4 Filed May 26, 1959 June 25, 1963 J. SZEKERES 3,094,909

REPRODUCTION APPARATUS Filed May 26, 1959 5 Sheets-Sheet 5 03 O o 8 0 LT.

"i II II II II II II II II II II II II M United States Patent 015 ice 3,094,909 Patented June 25, 1963 3,094,909 REPRODUCTION APPARATUS Janos Szekres, 19 Colony Court, Stamford, Conn. Filed May 26, 1959, Ser. No. 815,875 Claims priority, application Germany May 29, 1958 9 Claims. (Cl. 95-1.7)

This invention relates to an electrophotographic copying device. More specifically, to an efficient, compact copying device designed for use in areas of limited space or small business ofiices.

The use of electrophotography for reproduction purposes has increased greatly in recent years because of the many obvious advantages of such a process. Electrophotography is a dry reproduction method, and in contrast to the customary photographic methods there is no development of a latent chemical image in the developer liquid. Instead, a latent electric image is produced which is made visible by a process of electromechanical development, as for example, by dusting with a suitable dry developer in powder form.

In this connection an electrophotographic coating, for example, a semiconductive coating, is applied to a suitable base or support and is charged electrically, making it photo-sensitive. This coating is exposed to light by means of an exposure device and the original to be reproduced. This results in a differentiation of the coating into charged and uncharged areas to thus obtain a latent electric image. By sprinkling the treated film with a dry powder developer which may consist, for example, of a resin-soot mixture and which bears an electrical charge opposite to that on the photographic film, the image is made visible. The image is then fixed by the action of heat. The electromechanical development may also be effected in a liquid which contains the requisite blackening particles. For example, the liquid may comprise a solution of carbon tetrachloride with colloidal graphite.

If the image produced by the exposure is a mirror symmetrical image, it may be transferred (after it has been made visible as by dusting but before fixing) by pressing the image against a transfer paper. The transfer may constitute any suitable paper. Instead of pressing the image against a transfer paper, the image and the trans-fer paper may be placed in contact with each other in an electric field and thereby accomplish the desired transfer.

The direct symmetrical image then produced is fixed by action of heat. If a transparent material is used as a base for the electrophotographic coating, the transfer step may be omitted. In this instance, the image made visible by electromechanical development is fixed.

An electrophotographic copying device is known which employs a metal base in the form of an aluminum plate on which a coating of selenium is applied representing the electrophotographic coating. Such an electrophotographic plate is placed into a plateholder having a shutter or slide which is similar to the plate holders formerly used for photographing glass plates. The plate holder is first brought into a charging station where the electrophotographic paper is charged after opening the slide of the plate holder. The slide is then closed and the plate holder is transferred to an exposure station where it is exposed by a light source as from a movie projector or slide projector. Then the plate holder is put into a developing station, where it is sprinkled or dusted with the developing powder. The image thus produced is then transferred from the plate to a transfer paper by pressing the transfer paper on to the image at a transfer station. The transferred image is finally fixed at a fixing station by the action of heat. This type of device is not adaptable for use in small offices because of its high cost and very large size.

'In addition the process embodied in such a device is very slow and time consuming.

Others have suggested using an electrophotographic paper in which a coating composed of zinc oxide is applied on the paper base. The copying devices suggested for this purpose are somewhat similar in design to the above described copying device, with the exception that the electrophotographic paper is delivered from a roll. This type of electrophotographic device as with the above described device is also very cumbersome and very costly and thus not adaptable to use in small offices.

It is an object of the present invention to provide an electrophotographic copying device which is simple in construction and readily adaptable for use in small oflices.

Another object of this invention is to provide an electrophotographic copying device which is suitable for the production of copies from one or two sided originals.

A further object of this invention is to provide electrophotographic copying device which is fully automatic, and permits the production of copies in a very short time.

A still further object of this invention is to provide an electrophotographic device which is continuous in its operation.

It is yet another object of this invention to provide for a copying device having a unitary construction capable of continuously transporting the electrophotographic paper through all the various stations of charging, exposing, developing and transferring.

In its simplest form, my invention is characterized by a mechanically movable holding device which receives the electrophotographic paper and which passes upon movement through the successive stations where charging, exposure, developing and transfer (if desired) takes place. The holding device is provided with actuating means which engage corresponding elements at the various stations in such a way that the electrophotographic paper charged in the charging station is brought together at the exposure station with the original to be copied and exposed with the original in contact and in register with it; and further so that the electrophotographic paper, after separation from the original, is passed through a developing station and brought together with the transfer paper waiting at a transfer station and there exposed to a pressure which places the transfer paper in contact and in register with the electrophotographic paper having the developed image; after which the trans fer paper is separated from an electrophotographic paper and fixed at a fixing station. In case a direct symmetrical image is not required, the transfer step and station may be eliminated and the picture produced on the elec trophotographic paper may be fixed instead.

The holding device is comprised preferably of an arm, arranged transversely of and connected to a member mounted radially on and perpendicular to the longitudinal axis of the main drive shaft of the device, which arm is provided with fastening means for engaging the electrophotographic paper at its front edge (the leading edge in the direction of rotation of the arm and member). This parallel arm is connected either directly, or through the drive shaft with a gear segment which engages corresponding counter gears of the exposure and transfer station which drive a conveyor mechanism. In this way the conveyor mechanism for the original to be copied is put in motion in a very simple and efficient manner as the electrophotographic paper approaches the exposure station, so that the original is passed in synchronism and in register with the electrophotographic paper through the exposure station. Once the electrophotographic paper has arrived at the transfer station, the conveyor mechanism for the transfer paper is put in motion in a similar manner, so that this latter conveyor passes the transfer paper in synchronism and in registry with the exposed and developed electrophotographic paper through the transfer station. In addition, the holding device is so designed that it may control additional operations, for example, the connection of the current for the charging station, the lighting of the exposure lamps, and for opening the holding device to release the electropho-tographic paper.

The above and other objects and advantages of the invention will become apparent from a consideration of the following detailed description and accompanying drawings, wherein my preferred embodiments of the invention are found.

In the drawings:

FIG. 1 is a side view, partially in section, of a copying device according to one embodiment of my inven tion;

FIG. 2 is a side view of one modification of the holding device of another embodiment of the copying device which is illustrated in FIG. 6;

FIG. 3 is a front view of the holding mechanism shown in FIG. 2, viewing FIG. 2 from the left;

FIG. 4 is a side view, partially in section, of one embodiment of the pressure roll-er means for contacting the electrophotographic paper with the-original to be copied;

FIG. 5 is a side view, partially in section, of another embodiment of the pressure roller means shown in FIG. 4;

FIG. 6 is a side view partially in section of another embodiment of my copying device;

FIG. 7 is a plan view showing some of the features of the embodiment shown in FIG. 6;

FIG. 8 is a side view of one of the gears used with the embodiment shown in FIG. 6;

FIG. 9 is a side view of a second gear used with the embodiment shown in FIG. 6;

FIG. 10 is a plan view of some of the features of the embodiment shown in FIG. 6, emphasizing the arrangement of the stop mechanism used with the embodiment shown in FIG. 6.

Considering the embodiment shown in FIGURE 1, the holding device comprises a radial arm or member -1 rigidly connected at its one end to one end of the transverse drive shaft 7 such that the radial arm extends in a direction perpendicular to the longitudinal axis of the drive shaft. It will be understood that the ends of the drive shaft are mounted in suitable bearings to permit a smooth rotation of the shaft. The transverse arm 1 is connected to the other end of the radial arm 1', as shown in FIGURE 3, such that the transverse arm is substantially parallel to the transverse drive shaft 7 and such that it extends substantially across the width of the machine from that end of the drive shaft to which radial arm 1 is attached toward the opposite side. Rotation of the drive shaft 7 will cause the radial arm 1' and the transverse arm 1 to move also such that the transverse arm 1 will describe the path of a circle whose radius is equal to the length of radial arm 1. A full rotation of the shaft 7 in a clockwise direction will carry the holding device through all stations of the copying machine and return the holding device to its original position at the start of the cycle.

During this full revolution, the electrophotographic paper has been charged, exposed, developed, and the image transferred to ordinary paper and fixed by the application of heat. The driving means (not shown) may be automatically disconnected by any of the methods known after the shaft 7 has completed its full revolution of 360 degrees.

The method of operation basically is as follows: the electrophotographic paper is placed on the feed plate 2 and connected at its front edge to the transverse arm 1 of the holding device. The holding device may be provided, for example, with a plurality of hooks 3 which may engage corresponding holes or perforations of the paper and thus hold the electrophotographic paper. Instead of the hooks 3, a clamping device may also be used. This fastening of the electrophotographic paper must be inserted into the machine.

on the holding device insures a correct positioning and holding of the paper at all times and also insures the proper subsequent separation of the original from the electrophotographic paper.

The holding device is so mounted and interconnected to the other parts of my invention that the necessary closing of the electrical contacts and transfer of the electrophotographic paper takes place automatically upon proper movement of the holding device. In this way, no separate switching units are required, and the entire device embodying my invention remains small, compact, and yet eflicient.

Before connecting the drive motor to the drive shaft 7, the original paper to be copied and the transfer paper The paper to be copied may contain writing, drawings or the like on one or both sides. This original paper is inserted into the slot 4 until it abuts against a stop in such a way that the side to be copied points .to the left when viewing FIGURE 1. The original remains in this position until the transverse arm 1 reaches the vicinity of the exposure station with the electrophotographic paper.

The transfer paper is inserted into slot 5 until it abuts against a stop. The transfer paper remains in slot 5 until the transverse arm 1 reaches the vicinity of the transfer station at which time the transfer sheet starts moving in slot 5 and is placed in contact with the exposed and treated electrophotographic paper.

The operation of my device is as follows. The holding device comprising radial arm 1', and transverse arm 1 to which gear segment 6 is rigidly attached, either directly or through the drive shaft 7 as shown in FIG- URE 1, is caused to move upon rotation of the drive shaft 7. The clockwise rotation of shaft 7 then carries the holding device through the path of a circle. To insure that the holding device is properly engaged to the shaft and to avoid slippage, the shaft 7 is provided with a fiat extension 8 which mates with a corresponding slot in the lower portion of the holding device so as to provide a positive connection between the radial arm and the shaft.

with the attached paper begins to rotate in a clockwise manner, the paper passes under roller 9. This roller is yieldably mounted by means of a slotted bearing 10 so as to permit a relatively free passage of the holding device and the attached paper. The roller 9 is made of metal and is grounded to lead off any charges on the electrophotographic paper and to seal off the interior of the machine from any stray light which may enter through the inlet slot 11 of the device, since once the electrophotographic paper has been charged, it becomes photosensitive and would be adversely affected by stray light. The roller 9 also has the function of smoothing the paper to permit the placing of a uniform electrical charge at the charging station 12. The charging station 12 is operated for example, with a direct voltage of 6000 v. to 8000 v. and at about 1 milliampere. For safety purposes the charging station is surrounded by a grounded housing 13. The charging station comprises a smooth fixed, grounded metal curved surface 14 on which the electrophotographic paper glides firmly during the passage of the paper through the charging station. This is a prerequisite for a good and uniform charge.

The charging station has a plurality of very thin charging wires 12' of about 0.002 diameter, whose distance from the metal base 14 is such that a substantially great electrostatic charge is placed on the paper by means of a corona discharge taking place without sparkmg.

Since the transverse arm 1 is preferably made of metal, it may be necessary to connect the charging station only when the transverse arm 1 is passing through it. Otherwise undesirable spark discharges might occur between the charging wires 12' and the transverse arm 1 and the hooks 3. The connection and disconnection of the charging station can be effected by tripping pins secured on the gear segment 6 operating as a suitable switch.

As soon as the leadingedge of the paper secured to the arm 1 has passed through the charging station 12, it meets the original waiting in the slot 4, and both papers are conducted simultaneously and in register with each other through the exposure station. This synchronous travel occurs by virtue of the fact that gear segment 6, rigidly mounted to and moving with the holding device, engages the teeth of the counter gear mounted on one end of the shaft supporting conveyor roll 15.

Beneath and to one side of the roll 15 is arranged a second transport roll 17 which also has a counter gear on the shaft which supports it, and on the same side as the gear associated with roll 15, which is also arranged to mesh with gear segment 6. Between the rolls 15 and 17 an idler roller 18, as shown in FIGURE 1, is supported in a slotted bearing and resiliently urged away from the rollers 15 and 17. A conveyor belt 16' is entrained over the rolls 15, 17 and 18 with roller 18 acting also as the adjustable tension roller. The rolls 15 and 16 are in addition connected to each other by means of a gear chain 20. The speed of the conveyor belt 16 corresponds exactly to the speed of the transverse arm 1 and of the electrophoto-graphic paper. This may be achieved by using appropriate dimensions on gear segment 6 and the gears associated with the rolls 15 and 17.

The elect-ro-photographic paper with the original paper to be copied next glides over the curved glass plate 17a. Both papers are pressed firmly together by the conveyor belt 16. In order to increase the pressure of the conveyor belt 16 behind the holding device 1 the modification according to FIGURE 5 may be used.

It should be noted that when the transverse arm 1 moves along with the fastening means 3 so as to carry the electrophotographic paper and the original paper over the glass plate 1701, a small hollow space 52 is formed in the immediate vicinity of the arm 1 as illustrated in FIG- URE 4. This hollow space represents a no contact area between the pressure applying belt 16' and the associated papers and may impair the sharpness of the copy. In order to eliminate this disadvantageous condition, the modification illustrated in FIGURE 5 may be used.

The construction of this attachment is as follows. As soon as the transverse arm 1 with the electrophotographic paper secured thereon has passed the transport roll 15 of FIGURE 5 together with the original, a roller 53, which is secured to an engaging lever 54 and urged toward the plate 17a (said plate not shown in FIGURE 5) by a spring 55, presses the two papers against the glass plate 17a and eliminates the hollow space 52 indicated at FIGURE 4. The roll 53 is engaged by a projection on the finger 56 which is connected to the upper portion of arm 1. The engagement of this projection with roll 53 occurs over the entire surface of the exposure plate 17a. The control lever 54 is pivotally supported in a slot and pin arrangement as shown at 57. As soon as the roller 53 has arrived at the end of the exposure surface 17a, it is lifted by a fixed cam 58 so that it slides out of engagement with the projection on finger 56 and is returned to its original position by a spring (not shown in the drawing) so that it bears against the stop 59.

The exposure of the electrophotographic paper is effected by the lamp 18a shown in FIGURE 1. The lamp 18a is surrounded by a casing 19 which serves to keep out extraneous light. The inner surface of the case is designed as a reflector to better concentrate the light rays on the exposure plate. In order to regulate the time of exposure, the light intensity of the lamp 18a can be varied by a common variable resistance (not shown).

As the shaft 7 continues to rotate at constant speed, the electrophotographic paper and the original to be copied are carried through the exposure station. Likewise, the gear segment 6, which rotates with shaft 7, first engages the gear associated with the shaft of the roll 15 so as to initiate the movement of the conveyor belt 16'. The size of the gear segment 6 and the spacing between the rolls 15 and 17 is such that .the belt 16' is continuously driven until the gear segment 6 has completely passed the roll \17 and the gear associated with roll 17. This continuity of motion is insured by the chain drive 20 so that the belt 16' is driven as long as any part of moving gear segment 6 engages the gears of either rolls 15 or 17. Once the holding means is moved through the exposure station, the original is contacted by stripper means 21 which separates it from the exposed electrophotographic paper. The separated original then slides out chute 22.

The electrophotographic paper is next transported through the developing tank 23. The developing tank 23 is in the form of a semicircular trough which must be of such a depth as to hold sufficient developing means 24.

The developer 24 consists preferably of small glass balls which are mixed with a toner or dry developer powder (a fine powder consisting of resin and soot), in a ratio, for example, of 96 to 4, resin to soot, respectively. Instead of the dry developer aliquid solution may also be used with an electromechanical developer in the known manner. The solution, for example, may be carbon tetrachloride with colloidal graphite. If desired, a mixing or agitating mechanism may be provided in the tank 23 to constantly stir the developer.

The exposed electrophotognaphic paper secured on the transverse arm 1 is conducted by the arm 1' through the developing tank 23 in contact with the developer 24 and is developed during its long development path of about degrees of travel of the holding device.

Since the holding means is constructed with arm 1 perpendicular to arm 1 and parallel to shaft 7, it will be seen that by mounting arm 1 at the end of shaft 7, the two arms '1 and 1 assume a position substantially like that of an inverted L, with the arm :1 extending across the width of the machine. It will be understood then that as the holding means transports the exposed electrophotographic paper through the developer, the arm 1 cuts through the developer such that the developer is above and below the exposed paper. The weight of the developer on the upper surface of the exposed paper presses down upon it and insures a good contact between the lower exposed surface of the paper and the developer 24.

In another embodiment, the curved surface formed by the metal base 14 at the charging station is connected to the curved glass plate 17a at the exposure station and these two curved sections aresupplemented by a curved surface as that shown at 60. The curved surface 60 may be made of plastic or metallic material and is of such a diameter that when one end of it is attached to the lower portion of plate 17a adjacent roller 17, the other end will extend to and abut against the edge of plate 14 adjacent roll 9. In this manner the elements 14, 17a, and 60 are united so as to form a complete cylinder whose length extends substantially across the width of the machine. The total copying process then takes place about a cylinder whose surface at the charging station is provided with a conductive base and Whose surface at the exposure sta tion is transparent. The electrophotographic paper is conducted in this case about a full, fixed cylinder and comes in contact with the developer only on one side.

The gear segment 6 is so arranged that it lies outside the developing tank 23 and does not dip into the latter.

As soon as the arm 1 of the holding device has left the developing tank 23, it slides between the rolls 25 and 26. The roll 26 is so designed that it yields elastically in the same manner as roll 9 described above. The gear segment 6 connected with the arm 1' and the shaft 7 respectively engages now the gear at one end of the roll 25. The transfer paper waiting in the slot is then grasped and moved by roller 25 and placed in contact with the electrophotographic paper between the rolls 25 and 26 and pressed firmly together therebetween. The image pro duced by the development step on the electrophotographic paper is thus transferred to the transfer paper. A transfer on an offset printing plate is also possible, if so desired.

Care has to be taken, here too, that the peripheral speed of the roll 25 agrees with the speed of the arm 1, so that no relative motion takes place between the electrophotographic paper and the transfer paper, thereby retaining perfect register between the two papers. This is achieved by a corresponding dimensioning of the gear engagement between the gear segment and the teeth of the gear at the end of the roll 25.

While the elect-rophotographic paper secured on arm 1 of the holding device travels into the starting position of the holding device, the transfer paper provided with the transferred image is conducted through the slot 27 past a heating device 28 where the toner image is fused onto the face of the transfer paper and thus fixed. A stripper blade 61 is provided to insure that the transfer paper and the electrophotographic paper are separated.

After the arm 1' has returned into its starting position, the drive of the shaft 7 is automatically disconnected by suitable means. The cycle thus completed takes approximately 5 to 6 seconds. The exposed and developed electrophotographic paper may then be removed from engaging hooks 3.

In case transillumin-ation copies are desired, an additional lamp 29 may be provided as shown in FIGURE 1 inside the loop of conveyor belt 16'. The conveyor belt .16 must consist in this case of a light-transmissive material.

The size of the device depends on the size of the originals to be copied, and care has to be taken that the latter are always introduced into the slot 4 of the device with the longest side edge in a downward position so that this longest edge is contacted by the belt '16 first. In addition, the smallest side edge of the electrophotographic paper must not be longer than the circumferential path of the arm l1 over an angle of 90 degrees, otherwise the arm 1 will have arrived in its end position before the end of the electrophot-ographic paper has left the rolls 25 and 26. Naturally, the gear segment 6 connected with the arm 1 must also be so dimensioned that it does not engage the gear of the roll 25 at the time arm 1 has reached its end position. Due to this fact the above described embodiment has the limitation that the radius of the arm 1' must be relatively great when large originals are used, and the copying device consequently becomes correspondingly larger.

FIGURES 6 to show another embodiment of the eleotrophotographic copying device which may be used when large originals must be copied. This embodiment makes it possible to keep the dimensions of the device small enough such that the overall size of the device is substantially that of an ordinary typewriter even in the case where large originals must be used.

In the embodiment according to FIGURE 1 both the rolls and 1 7 of the exposure station and the roll of the transfer station were driven by the sarne gear segment 6. In the embodiment according to FIGURE 6 two separate but identically sized gear segments 42 and 42' are substituted for gear segment 6; each of these two gears extends substantially over an angle of about 315 degrees; the gears are arranged at opposite ends of the shaft 7 as shown in FIGURE 7. The front gear segment 42 (as viewed in FIG. 6) engages a counter gear associated with the roll 15, while the back gear segment 42 on the other side engages a counter gear associated with the stereos roll 25. Both gear segments 42, 42 are driven by the continuously rotating shaft 7 through friction couplings or plates 43, 45, as soon as appropriate retention pins are retracted. With this arrangement it is possible to process papers whose smallest side is equal to a peripheral path of the transverse arm 1 over an angle of 270 degrees in stead of 90 degrees. For simplicity of illustration, the roll 9 of FIGURE 1, and the elements of the charging and exposure station have not been shown in FIGURE 6. All these elements correspond exactly to what is shown in FIGURE 1.

The holding device for the electrophotographic paper is preferably designed in this embodiment as represented in FIGURES 2 and 3 although it should be understood that the holding means of FIGURES 2 and 3 may also be used with the embodiment shown in FIGURE 1, as well. Over the extended arm 1 is arranged a clamping strip 39 which is connected with a radial arm 30 arranged parallel to and in contact with arm 1. The radial arm 30 can slide relatively to the radial arm 1' by means of the pins 31 and 32 secured to arm 30' and adapted to slide in slots 33, 34. When the clamping strip 30 is in the position shown in FIGURE 3, the electrophotographic paper 35 can be inserted into the holding device or removed therefrom. The paper 35 is held in the clamped position by conical pins 36 which engage corresponding recesses as 37 of the extended arm 1 and which hold the paper 35 firmly in the position of FIGURE 2. In order to retain the clamping strip 30 in the clamping position shown, a pivotally mounted pawl 38 is provided. The pawl has a hook portion as at 33' at the end opposite the pivotal connection which hook portion is adapted to engage pin 31 thus holding the clamping strip 30 in the down or engaging position. A spring as 40 is provided which contacts pawl 38 and urges it into the upright engaging position as shown in FIGURE 2. The spring 40 retains the pawl 38 in engagement with pin 31 of arm 30' and the clamping strip 30 until a release pin pushes the pawl out of engagement thus allowing the clamping strip to rise and assume the position shown in FIGURE 3 due to the action of spring 39 which constantly urges arm 30 and clamping strip 30 upwardly into the disengaged position. The closing of the clamping device is effected by hand by pressing down on the clamping strip 30 thereby permitting the spring 40 to urge the pawl 38 automatically into engagement with pin 31.

In the embodiment according to FIGURE 6, the clamping device represented in FIGURES 2 and 3 is released automatically. This automatic release is necessary because the gear segment 42 of FIGURE 6, which drives the gear of the roll 15, is 315 degrees, while its circumference in the embodiment according to FIGURE 1 is only about degrees. With the device according to FIGURE 6 it is therefore possible to perform the copying process much faster.

In the embodiment according to FIGURE 6, the arms 1 and 1' are rigidly connected to the first or front gear segment 42 which is connected to one side of the first fric tion coupling; the other side of this friction coupling is connected to shaft 7. The second or rear segment 42' is connected to one side of the second friction coupling; the other side of the latter is also connected to shaft 7. The friction couplings between the shaft 7 and the gear segments 42, 42 are so adjusted by means of the nuts 44 and the spider spring plates 45 that rotation of the rear segments and of the devices actuated by them is insured as soon as the gear segments are released. The driving motor must be somewhat stronger than in the first embodiment, because it must be capable of overcoming the friction of the coupling of the stationary second gear segment 42' adapted to drive the roll 25, While driving at the same time the first gear segment 42 and the roll 15. This condition exists after the first gear segment (42) begins to rotate but before the second gear segment 42 is released.

The method of operation of the device according to FIGURE 6 is as follows. The electrophotographic paper is put on the plate -2 and connected to the transverse arm 1 by pressing down the clamping strip 30.

The driving motor connected to shaft 7, when started, will not drive the gear segments 42 and 42' until the retaining pins 46 and 47 interposed in the paths of the first gear segment 42 and the second gear segment 42, respectively, are retracted into a non-interposing position. It will be understood that the friction couplings or plates will provide the necessary slippage to prevent damage to the machine when the driving force of the motor is applied to the shaft 7 at the times when the retaining pins 46, 47 prevent any rotary motion of the segments 42 and 42.

The original paper to be copied is inserted into slot 4 and the transfer paper into slot 5 as described above in connection with the embodiment of FIGURE 1.

The retaining pin 46 is now retracted by a hand-operated lever (not shown in the drawing). The first gear segment 42 (which drives the roll 15) then begins to move in a clockwise direction (viewing FIGURE 6). The arm 1 carrying the electrophotographic paper passes through the charging station 12, meets the original and takes it along in the same manner as described above, because the first gear segment 42 engages the gear at the end of the roll 15. A chain connection between the rolls 15 and 17 is not necessary in this embodiment since the gear segment 42 is of sufiicient size and is so arranged as to be able to transport the electrophotographic paper and original over the entire surface of the exposure plate (17a) by the interaction of gear 42 with the gear at the end of roll 15.

The stripping of the original and its ejection is efiected in the same manner as in the first embodiment. The developing process is also the same.

As soon as the radial arm 1' has arrived in front of the roll 25, it pushes back the retention pin 47 (or a pin connected to pin 47) for retaining the second gear segment 42', so that the latter is now also connected through its friction clutch plate to the shaft 7. The teeth of gear segment 42 engage the gear of the transfer roll 25. The construction of the friction clutch or plate is well known in technology so that a detailed description is considered unnecessary. For claritys sake, that part of the second gear segment 42' which has no teeth is hatched as shown in FIGURE 6.

The transfer paper which was placed in the slot 5 is now conducted, together with the developed electrophotographic paper, between rolls 25 and 26, and the developed image is transferred to the transfer paper. Th transfer paper slides now through the slot 27 past the heating device 28, where it is fixed and moves then out. The arm 1 with the clamped electrophotographic paper is released. At the same time the pawl 48 releases the yoke so that the spring loaded yoke 49 snaps back in the direction of the arrow in FIGURE 6, and the electrophotographic paper is removed from the clamping device and brought into position shown in FIGURE 6 at 35. The electrophotographic paper is supported by plate 50 and issues through the slot 51 from the copying device. The electrophotographic paper 35 is now moved only by the rolls 25 and 26, completely independent of the motion of the arm 1. While the combined arms 1 and 1 return to their starting position, where they are retained by the retention pin 46, the electrophotographic paper 35 and the transfer paper move along in the slots 51 and 27, respectively, until the transfer process taking place between the rolls 25 and 26 is completed and the second gear segment has arrived in its starting position where it is retained by the retention pin 47.

By a projection on the second gear segment (not represented in the drawing) the yoke 49 is returned to its starting position, shortly before this segment has completed itspath, where it is again held by the pawl 48.

In the meantime a new electrophotographic paper can be clamped into the clamping device, and the operation may begin again, after a new original and new transfer paper have been inserted into" the slots 4 and 5, respec tively.

The invention is not limited to the embodiments represented and described above, but also comprises modifications which are within the spirit of the inventive idea. Thus, for example, if transfer to a transfer paper is not desired, the transfer station can be eliminated and instead the developed electrophotographic paper itself may be fixed.

I claim:

1. An electrophotographic copying device comprising in combination, a support, means for moving said support through a fixed path, holding means mounted on said support for attaching an electrophotographic paper to said support for movement with said support through said fixed path, means on said support for readily moving said holding means in a first direction for attaching an electrophotographic paper to said support when said support is at a first preset position in said fixed path and for readily moving said holding means in a second direction for releasing said paper from said support when said support is at a second preset position in said fixed path, electrical discharge means in communication with and lying along said fixed path for charging said paper as said paper moves in said path past said discharging means, transport means adjacent said discharge means and lying along one side of said fixed path for moving material to be copied into and out of engagement with said electrophotographic paper in said fixed path, feed means for delivering material to be copied to said transport means, photosensitive material exposure means along said path on the side of said path opposite said transport means for exposing said electrophotographic paper as said paper and said material to be copied move through said transport means in said fixed path, a translucent plate in said path intermediate said transport means and said exposure means, and reservoir means in said fixed path adjacent said exposure means for receiving said paper from said exposure means.

2. An electrophotographic copying device of the character described in claim 1 in which said transport means comprises belt means driven in synchronism with the movement of said support.

3. An electrophotographic copying device comprising in combination, a movable support, means for moving said support through a fixed path, holding means on said support for attaching an electrophotographic paper tosaid support, means on said support for readily moving said holding means in a first direction for attaching an electrophotographic paper to said support When said support is at a first preset position in said fixed path and for readily moving said holding means in a second direction for releasing said paper from said support when said support is at a second preset position in said fixed path, electrical discharge means communicating with and lying along the path of movement of said holding means for charging said paper as said paper moves in said path past said discharge means, transport means adjacent to said discharge means and lying along one side of the path of movement of said holding means for moving material to be copied into and out of engagement with said paper, feed means between said discharge means and said transport means for feeding material to be copied to said transport means, a first photosensitive material exposure means along said path on the side of said path opposite to said transport means, a second photosensitive material exposure means opposite said exposure means and located such that said transport means is substantially between said first and second exposure means, a translucent plate in said path intermediate said first and second exposure means, and reservoir means adjacent to said transport means and lying along the path of movement of said holding means 4. An electrophotographic copying device of the character described in claim 3 in which said transport means comprises endless conveyor means driven in synchronism 11 with the movement of said holding means and said conveyor means is made of light transmissive material.

5. An electrophotographic copying device comprising in combination, a movable support, holding means on said support for attaching an electrophotographic paper to said support, means on said support for readily moving said holding means in a first direction for attaching an electrophotographic paper to said support when said support is at a first preset position and for readily moving said holding means in a second direction for releasing said paper from said support when said support is at a second preset position, a first gear means mounted for movement with said support and said holding means, electrical discharge means communicating with and lying along the path of movement of said holding means, transport means adjacent to said discharge means and on one side of said path for moving material to be copied into and out of engagement with said paper, second gear means connected to said transport means and engageable by said first gear means to move said transport means in timed relation to the movement of said holding means, feed means between said discharge means and said transport means for delivering material to be copied to said transport means, photosensitive material exposure means along said path on the side of said path opposite to said transport means for exposing said paper as said paper and said material to be copied move through said transport means, a translucent plate in said path intermediate said exposure means and said transport means, and reservoir means adjacent to said transport and exposure means and lying along the path of movement of said holding means for receiving said paper from the exposure means.

6.- An electrophotographic copying device comprising in combination, a support, means for moving said support through a fixed path from an initial position to a final position, holding means mounted on said support for attaching an electrophotographic paper to said support, means on said support for readily moving said holding means in a first direction for attaching an electrophotographic paper to said support when said support is at said initial position in said fixed path and for readily moving said holding means in a second direction for releasing said paper from said support when said support is at said final position in said fixed path, electrical discharge means communicating with and lying along said path adjacent to said initial position of said holding means for charging said paper as said paper moves in said path past said discharge means, a first transport means adjacent to said discharge means and lying along one side of said path for moving material to be copied into and out of engagement with said electrophotographic paper as said paper moves in said path, a first feed means between said discharge means and said first transport means and communicating with said first transport means for delivering material to be copied to said transport means, photosensitive material exposure means along said path on the side of said path opposite to said first transport means for exposing said paper when said material to be copied is in engagement therewith, a translucent plate in said path intermediate said transport means and said exposure means, reservoir means adjacent to said first transport means and exposure means and lying along the path of movement of said holding means for receiving said paper from said exposure means, a second transport means adjacent to said reservoir means and lying along the path of movement of said holding means for moving transfer paper into and out of engagement with said exposed electrophotographic paper, and a second feed means between said reservoir means and said second transport means and communicating with said second transport means for delivering transfer paper to said second transport means.

7. An electrophotographic copying device comprising in combination, a support, means for moving said support through a fixed path, holding means mounted on and movable with said support through said fixed path from an initial position to a final position, means on said support for readily moving said holding means in a first direction for attaching an electrophotographic sheet to said support when said support is at said initial position and in a second direction for readily releasing said sheet from said support when said support is at said final position, electrical discharge means communicating with and lying along said fixed path of movement and adjacent to said initial position, a first transport means adjacent to said discharge means and lying along one side of said fixed path for delivering material to be copied into and out of said fixed path, a first feed means between said discharge means and said first transport means for feeding said material to be copied to said first transport means, a first photosensitive material exposure means along said path and opposite to said first transport means, a second photosensitive material exposure means opposite said first exposure means and located such that said first transport means is substantially between said first and second exposure means, translucent means intermediate said first and second exposure means, reservoir means adjacent to said first transport means and lying along said fixed path, a second transport means adjacent to said reservoir means and lying along said fixed path for delivering transfer material into and out of said fixed path, and a second feed means adjacent to said second transport means for feeding said transfer material to said second transport means.

8. An electrophotographic copying device of the character described in claim 7, in which said first transport means comprises a light transmissive endless conveyor.

9. An electrophotographic copying device comprising in combination, a movable support, holding means mounted on and movable with said support through a fixed path from an initial position to a final position, means for readily moving said holding means in a first direction for attaching an electrophotographic paper to said support when said support is in said initial position and in a second direction for readily releasing said paper from said support when said support is in said final position, electrical discharge means communicating with and lying along said fixed path and adjacent to said initial position of said holding means, a first transport means adjacent to said discharge means and lying along one side of said fixed path for delivering material to be copied into and out of said fixed path, a first feed means between said discharge means and said first transport means for feeding material to be copied to said first transport means, photosensitive material exposure means along said path on the side of said path opposite to said first transport means, translucent means in said path intermediate said first transport means and said exposure means, reservoir means adjacent to said first transport means and exposure means and lying along said fixed path, a second transport means adjacent to said reservoir means and lying along said fixed path for delivering transfer material into and out of said fixed path, a second feed means between said reservoir means and said second transport means for feeding transfer material to said second transport means, and electrophotographic fixing means adjacent to and associated with said second transport means such that said fixing means lies between said second transport means and said final position of said holding means in said fixed path.

References Cited in the file of this patent V UNITED STATES PATENTS 2,357,809 Carlson Sept. 12, 1944 2,573,881 Walkup et al. Nov. 6, 1951 2,885,556 Gundlach May 5, 1959 2,885,955 Vyverberg May 12, 1959 2,922,883 Giaimo Jan. 26, 1960 

1. AN ELECTROPHOTOGRAPHIC COPYING DEVICE COMPRISING IN COMBINATION, A SUPPORT, MEANS FOR MOVING SAID SUPPORT THROUGH A FIXED PATH, HOLDING MEANS MOUNTED ON SAID SUPPORT FOR ATTACHING AN ELECTROPHOTOGRAPHIC PAPER TO SAID SUPPORT FOR MOVEMENT WITH SAID SUPPORT THROUGH SAID FIXED PATH, MEANS ON SAID SUPPORT FOR READILY MOVING SAID HOLDING MEANS IN A FIRST DIRECTION FOR ATTACHING AN ELECTROPHOTOGRAPHIC PAPER TO SAID SUPPORT WHEN SAID SUPPORT IS AT A FIRST PRESET POSITION IN SAID FIXED PATH AND FOR READILY MOVING SAID HOLDING MEANS IN A SECOND DIRECTION FOR RELEASING SAID PAPER FROM SAID SUPPORT WHEN SAID SUPPORT IS AT A SECOND PRESET POSITION IN SAID FIXED PATH, ELECTRICAL DISCHARGE MEANS IN COMMUNICATION WITH AND LYING ALONG SAID FIXED PATH FOR CHARGING SAID PAPER AS SAID PAPER MOVES IN SAID PATH PAST SAID DISCHARGING MEANS, TRANSPORT MEANS ADJACENT SAID DISCHARGE MEANS AND LYING ALONG ONE SIDE OF SAID FIXED PATH FOR MOVING MATERIAL TO BE COPIED INTO AND OUT OF ENGAGEMENT WITH SAID ELECTROPHOTOGRAPHIC PAPER IN SAID FIXED PATH, FEED MEANS FOR DELIVERING MATERIAL TO BE COPIED TO SAID TRANSPORT MEANS, PHOTOSENSITIVE MATERIAL EXPOSURE MEANS ALONG SAID PATH ON THE SIDE OF SAID PATH OPPOSITE SAID TRANSPORT MEANS FOR EXPOSING SAID ELECTROPHOTOGRAPHIC PAPER AS SAID PAPER AND SAID MATERIAL TO BE COPIED MOVE THROUGH SAID TRANSPORT MEANS IN SAID FIXED PATH, A TRANSLUCENT PLATE IN SAID PATH INTERMEDIATE SAID TRANSPORT MEANS AND SAID EXPOSURE MEANS, AND RESERVOIR MEANS IN SAID FIXED PATH ADJACENT SAID EXPOSURE MEANS FOR RECEIVING SAID PAPER FROM SAID EXPOSURE MEANS. 